[orx-shapes] Refactor package layout

orx-shapes/src/commonMain/kotlin/primitives/Arc.kt

@@ -0,0 +1,33 @@
+package org.openrndr.extra.shapes.primitives
+
+import org.openrndr.math.*
+import org.openrndr.shape.ShapeContour
+import org.openrndr.shape.contour
+
+/**
+ * A circular arc
+ */
+class Arc(val center: Vector2, val radius: Double, val angle0: Double, val angle1: Double) : LinearType<Arc> {
+    fun position(t: Double): Vector2 {
+        val angle = mix(angle0, angle1, t.clamp(0.0, 1.0))
+        return Polar(angle, radius).cartesian + center
+    }
+
+    val contour: ShapeContour
+        get() {
+            return contour {
+                moveTo(position(0.0))
+                circularArcTo(position(0.5), position(1.0))
+            }
+        }
+
+    override fun div(scale: Double) = Arc(center / scale, radius / scale, angle0 / scale, angle1 / scale)
+
+    override fun times(scale: Double) = Arc(center * scale, radius * scale, angle0 * scale, angle1 * scale)
+
+    override fun plus(right: Arc) =
+        Arc(center + right.center, radius + right.radius, angle0 + right.angle0, angle1 + right.angle1)
+
+    override fun minus(right: Arc) =
+        Arc(center - right.center, radius - right.radius, angle0 - right.angle0, angle1 - right.angle1)
+}